/*
 * @(#)CompoundEnumeration.java	1.11 06/10/10
 *
 * Copyright  1990-2008 Sun Microsystems, Inc. All Rights Reserved.  
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER  
 *   
 * This program is free software; you can redistribute it and/or  
 * modify it under the terms of the GNU General Public License version  
 * 2 only, as published by the Free Software Foundation.   
 *   
 * This program is distributed in the hope that it will be useful, but  
 * WITHOUT ANY WARRANTY; without even the implied warranty of  
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU  
 * General Public License version 2 for more details (a copy is  
 * included at /legal/license.txt).   
 *   
 * You should have received a copy of the GNU General Public License  
 * version 2 along with this work; if not, write to the Free Software  
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  
 * 02110-1301 USA   
 *   
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa  
 * Clara, CA 95054 or visit www.sun.com if you need additional  
 * information or have any questions. 
 *
 */

package sun.misc;

import java.util.Enumeration;
import java.util.NoSuchElementException;

/*
 * A useful utility class that will enumerate over an array of
 * enumerations.
 */
public class CompoundEnumeration implements Enumeration {
    private Enumeration[] enums;
    private int index = 0;

    public CompoundEnumeration(Enumeration[] enums) {
	this.enums = enums;
    }

    private boolean next() {
	while (index < enums.length) {
	    if (enums[index] != null && enums[index].hasMoreElements()) {
		return true;
	    }
	    index++;
	}
	return false;
    }

    public boolean hasMoreElements() {
	return next();
    }

    public Object nextElement() {
	if (!next()) {
	    throw new NoSuchElementException();
	}
	return enums[index].nextElement();
    }
}
